JP5996346B2 - Commutator - Google Patents

Description

  The present invention relates to a commutator.

  The commutator of a direct current motor has a cylindrical insulator fixed to the rotating shaft of the armature, and a plurality of conductive segments attached to the outer peripheral surface of the insulator. Each segment is provided with a riser to which ends of coils wound around the armature core are connected. A power supply brush is slidably contacted with the outer peripheral surface of the segment. DC power applied from the power supply brush is supplied to the coil of the armature through the segment. By the way, as such a commutator, what is disclosed by patent document 1, for example is known. The segment of the commutator of Patent Document 1 includes a claw portion in which both end portions of the segment are bent inward in the radial direction of the insulator. Each segment is bonded to the insulator with the claw portion buried in the insulator.

JP-A-8-308182

  By the way, when the commutator rotates, a centrifugal force acting in the radial direction of the rotating shaft acts on the segment. On the other hand, since the nail | claw part is formed by bending, it has the inclined surface inclined with respect to the radial direction of a rotating shaft. Therefore, when the commutator rotates, centrifugal force acts on the inclined surface of the claw portion. The centrifugal force is decomposed into a component along the inclined surface and a component perpendicular to the inclined surface. For this reason, the component of centrifugal force acts in the direction along the inclined surface, that is, the direction in which the claw portion falls off the insulator. For this reason, there exists a possibility that a segment and an insulator may space apart.

  This invention is made | formed in view of such the actual condition, The objective is to provide the commutator which suppresses separation | spacing with a segment and an insulator.

In order to solve the above-mentioned problem, the invention of claim 1 includes a cylindrical insulator and a plurality of commutator pieces made of a conductive plate and arranged in parallel in the circumferential direction on the outer peripheral surface of the insulator. The commutator piece is bent from one end in the axial direction of the insulator toward the radially outer side of the insulator, and a connection claw to which an armature winding is electrically connected, and the insulation body bent radially inward of the insulator from both ends in the axial direction of the commutator and a locking pawl for locking the insulator, the locking claw, each commutator segment A pair of first locking claws provided on both ends of the connecting claws in the axial direction and on both sides of the connecting claws in the circumferential direction, and opposite to the connecting claws in the axial direction of each commutator piece Each of the commutators includes a pair of second locking claws provided at the ends of the commutator. The pair of first locking claws extend toward the second locking claws paired with each other in the axial direction, and in each commutator piece, the pair of first locking claws In addition, a notch that opens to the adjacent commutator piece side is formed only on the side part on the side opposite to each other and on the side of the adjacent commutator piece side in the circumferential direction, The pair of second locking claws are provided on the side of the commutator piece adjacent to the side of the commutator piece adjacent to the side of the commutator piece adjacent to each other in the circumferential direction. notch for opening is formed, the notch of the first locking claw and the second locking claw is configured as gripper for obtaining the anchor effect between the insulator and said Rukoto.

According to this configuration, since the anchor effect is exhibited by the grip portion (notch) , the displacement of the first and second locking claws in the removal direction is restricted. As a result, the separation between the commutator piece and the insulator is suppressed .

According to this configuration, the direction in which the paired first locking claw and second locking claw are removed is opposite. For this reason, since the force which the commutator piece and the insulator try to separate cancels, the commutator piece is more difficult to separate from the insulator.

  The commutator of the present invention has an effect of suppressing the separation between the segment and the insulator.

The perspective view which shows a commutator. The perspective view which shows the raw material of a segment. (A)-(c) is sectional drawing which shows the 1st-3rd groove | channel. (A)-(c) is sectional drawing which shows the formation process of a groove | channel. The perspective view which shows the raw material of a segment. The perspective view which shows a cylindrical raw material. The perspective view which shows the state which bent the riser and middle nail | claw of the cylindrical material. Sectional drawing of the segment in the position of a notch. The top view which shows the segment of another example. Sectional drawing which shows the segment of another example.

Hereinafter, an embodiment embodying the commutator of the present invention will be described with reference to FIGS.
As shown in FIG. 1, the commutator 10 includes a cylindrical insulator 11 made of a thermosetting resin and ten segments 12 fixed to the outer peripheral surface of the insulator 11. A press-fit hole 11 a penetrating in the axial direction is provided at the radial center of the insulator 11. A rotary shaft of an armature (not shown) is press-fitted into the press-fitting hole 11a. Thereby, the commutator 10 rotates integrally with the rotating shaft of the armature.

  Each segment 12 is formed of a conductive metal plate material (for example, a copper plate). The ten segments 12 are arranged in parallel at equal angular intervals in the circumferential direction of the insulator 11 and are formed in a strip shape extending in the axial direction of the insulator 11. A dividing groove 13 extending in the axial direction of the insulator 11 is provided between the adjacent segments 12. The adjacent segments 12 are separated from each other by the dividing groove 13. That is, the ten segments 12 are electrically insulated from each other. Each dividing groove 13 is formed deeper inward in the radial direction than the thickness of each segment 12 (the radial thickness of the insulator 11). That is, each dividing groove 13 is formed up to the insulator 11.

  A riser 14 is provided at one end of each segment 12 in the axial direction (upper end in FIG. 1). The riser 14 is bent outward from the base end in the radial direction of the insulator 11. The riser 14 faces the radially outer surface of the segment 12. The riser 14 is connected to an armature coil that constitutes an armature (not shown).

  Two first middle claws 15 are provided at the end of each segment 12 on the riser 14 side. The two first middle claws 15 are provided so as to sandwich the riser 14. On the other hand, two second intermediate claws 16 are provided at the end of each segment 12 opposite to the end where the riser 14 is provided. The two second middle claws 16 are provided at positions that are paired with the two first middle claws 15 in the longitudinal direction of the segment 12. The first and second middle claws 15, 16 are bent from the base end to the side opposite to the riser 14, that is, radially inward of the insulator 11. The distal ends of the first and second middle claws 15 and 16 face the radially inner surface of the segment 12. The distal ends of the first and second middle claws 15 and 16 are embedded in the insulator 11. Thereby, each segment 12 is connected to the insulator 11. In addition, as shown in FIG. 7, the notch 17 opened to the adjacent segment 12 side is provided in the side part of the 1st and 2nd middle nail | claws 15 and 16. As shown in FIG.

  As shown in FIG. 2, a groove 30 is provided on the surface of the segment 12 on the insulator 11 side. The groove portion 30 is constituted by two groove rows 31 provided along the longitudinal direction of the segment 12. Each of the two groove rows 31 includes eight first grooves 32, five second grooves 33, and three third grooves 34. The first to third grooves 32 to 34 are provided in this order from the end of the segment 12 on the side opposite to the riser 14. As shown in FIGS. 3A to 3C, the first to third grooves 32 to 34 are triangular grooves that become sharper as the distance from the contact surface with the insulator 11 increases.

  As shown in FIG. 3A, when the trough of the triangular groove is the apex, and the line extending to the longitudinal riser side of the segment 12 so as to pass through this apex is the reference line (0 °), the first groove 32 Is formed over 30 ° to 80 °. The surface along 80 ° of the first groove 32 is an undercut 32a. Undercut refers to a shape in which an opening protrudes above the bottom of a groove. The distance between the valley portion of the first groove 32 and the contact surface of the insulator 11, that is, the depth of the first groove 32 is 30% (0.3 t) of the plate thickness t.

  As shown in FIG.3 (b), the 2nd groove | channel 33 is formed over 100 degrees-150 degrees. The surface along 100 ° of the second groove 33 is an undercut 33a. The distance between the valley portion of the second groove 33 and the contact surface of the insulator 11 is 30% (0.3 t) of the plate thickness t.

  As shown in FIG.3 (c), the 3rd groove | channel 34 is formed over 100 degrees-150 degrees. The surface along the 100 ° of the third groove 34 is an undercut 34a. The distance between the valley of the third groove 34 and the contact surface of the insulator 11 is 50% (0.5 t) of the plate thickness t.

Next, a method for manufacturing the commutator 10 will be described.
As shown in FIGS. 4 (a) and 4 (b), first, the metal plate material 20 in a state where the wedge-shaped punch 9 having the tip portion angle of 50 ° and the plate surface has an angle of 30 °. Press against. Thereafter, as shown in FIG. 4C, the punch 9 is pulled out. Thereby, the first groove 32 is formed. Although not shown, the second and third grooves 33 and 34 are formed in the same manner as the first groove 32 only by changing the angle of the punch 9 from the plate surface to 150 °. . By repeating this, the metal plate material 20 becomes the metal plate material 20 in which the groove 30 shown in FIG. 5 is formed.

  Next, as shown in FIG. 5, a punching material 21 is punched from the metal plate material 20. The punching material 21 is formed in a substantially rectangular shape. Ten risers 14 and 20 first middle claws 15 are provided on one end surface of each punching material 21 in the short direction (a direction orthogonal to the longitudinal direction), and 20 second middle claws are provided on the other end surface. 16 are formed respectively. The risers 14 are formed at equal intervals in the longitudinal direction of the punched material 21. The first middle claw 15 is formed on both sides of the riser 14. The second middle claw 16 is formed at a position facing the first middle claw 15. Further, the first and second middle claws 15 and 16 are formed with notches 17. At this time, if the width (in the direction orthogonal to the axial length) and the interval of the second middle claw 16 are the same as those of the first middle claw 15, the feed pitch in the longitudinal direction of the material can be reduced, and the yield is extremely high. be able to.

  Next, the blanking material 21 is rounded to form the cylindrical material 22 shown in FIG. At this time, the riser 14 and the first and second middle claws 15, 16 have a linear shape parallel to the axis of the cylindrical material 22.

  After that, as shown in FIG. 7, each riser 14 is bent radially outward and shaped so that the tip thereof faces the axial center of the cylindrical material 22. Further, the first and second middle claws 15, 16 are bent inward in the radial direction, and are formed so that the front end portions thereof face the central portion in the axial direction of the cylindrical material 22.

Thereafter, a thermosetting resin is filled into the cylindrical material 22 using a mold (not shown). After filling, the resin is cured by a chemical reaction to form the insulator 11 shown in FIG.
Then, the dividing material 13 (refer FIG. 1) is shape | molded along the axial direction in the several places of the outer peripheral surface of the cylindrical raw material 22 integral with the insulator 11, and the cylindrical raw material 22 is cut | disconnected. Thereby, ten segments 12 electrically insulated from each other are formed, and the commutator 10 shown in FIG. 1 is completed.

Next, the operation of the commutator 10 will be described.
As shown in FIG. 2, notches 17 are provided in the first and second intermediate claws 15 and 16. As shown in FIG. 8, the insulator 11 penetrates into the notch 17 between the distal end portions 15 a and 16 a and the proximal end portions 15 b and 16 b in the first and second intermediate claws 15 and 16. For this reason, even if the segment 12 tries to separate from the insulator 11 due to the centrifugal force accompanying the rotation of the commutator 10, the tip portions 15a and 16a are caught on the insulator 11 (anchor effect). Here, in a commutator having a small outer diameter and a commutator having a large number of segments, the width of the segment 12 is narrow. Since the riser 14 is a part connected to the armature coil, it is difficult to make the riser 14 narrow in accordance with the width of the segment 12 because the strength is lowered. Accordingly, the widths of the first and second intermediate claws 15 and 16 are reduced in accordance with the width of the segment 12. As the width becomes narrower, the strength of the root portions of the first and second middle claws 15 and 16 decreases. When the strength of the root portions of the first and second middle claws 15 and 16 is reduced with respect to the resin strength, the first and second middle claws 15 and 16 are segmented by the centrifugal force accompanying the rotation of the commutator 10. 12 attempts to deform in a direction away from the insulator 11. However, since the insulator 11 is filled in the notch 17, the anchor effect suppresses the deformation of the first and second intermediate claws 15, 16, and the segment 12 and the insulator 11 are separated from each other. It is suppressed.

  In addition, since the anchor effect is exhibited by the notch 17, the length of the first and second middle claws 15, 16 is made shorter than the length of the conventional middle claws without the notch so as to insulate the segment 12. The amount of material of the segment 12 can be reduced while suppressing the separation from the body 11.

  In addition, as shown in FIG. 2, the notch 17 is provided on the side of the first middle claw 15 so as to open to the adjacent segment 12 side, that is, the side opposite to the riser 14. The notch 17 is formed when the metal plate material 20 is punched out. For this reason, if the notch 17 is to be provided on the riser 14 side, the punch may interfere with the riser 14 if the punching position is shifted even a little. When the punch interferes with the riser 14, the riser 14 is provided with a notch. As a result, the strength of the riser 14 may be reduced. As a result, the electrical connection between the riser 14 and the armature coil is canceled, and the function as the commutator 10 may not be exhibited. In that respect, since the notch 17 of this example is provided so as to open on the opposite side to the riser 14, there is no possibility that the riser 14 interferes with the punch due to a slight shift of the punch position. That is, since the dimensional accuracy can be set loosely, the occurrence rate of defective products in the manufacturing stage is reduced.

  The pair of first and second middle claws 15 and 16 are each bent toward the longitudinal center of the segment 12. Therefore, as shown in FIG. 8, when the segment 12 and the insulator 11 are separated from each other, the removal direction of the first middle claw 15 and the removal direction of the second middle claw 16 are substantially opposite directions. That is, the force for separating the segment 12 and the insulator 11 is canceled out. For this reason, the separation between the segment 12 and the insulator 11 is further suppressed.

As described above in detail, according to the present embodiment, the following effects can be obtained.
(1) The insulator 11 penetrates into the notch 17 provided between the distal end portions 15a, 16a and the proximal end portions 15b, 16b in the first and second intermediate claws 15, 16. For this reason, even if the segment 12 tries to be separated from the insulator 11, the tip portions 15a and 16a are caught by the insulator 11 (anchor effect). Thereby, the first and second middle claws 15 and 16 are not separated from the insulator 11. As a result, the separation between the segment 12 and the insulator 11 is suppressed.

  (2) Since the anchor effect is exhibited by the notch 17, the lengths of the first and second middle claws 15, 16 can be made shorter than the length of the conventional middle claws without the notch. In addition, it is possible to deal with a narrow type segment. Thereby, the amount of material of the segment 12 can be reduced while suppressing the separation between the segment 12 and the insulator 11.

  (3) The notch 17 is provided so as to open on the opposite side of the riser 14 in the first middle claw 15. Thereby, there is no possibility that the riser 14 interferes with the punch due to a slight shift of the punch position. That is, since the dimensional accuracy can be set loosely, the occurrence rate of defective products in the manufacturing stage is reduced.

  (4) The paired first and second middle claws 15 and 16 are each bent toward the longitudinal center of the segment 12. For this reason, the removal direction of the first middle claw 15 and the removal direction of the second middle claw 16 are substantially opposite directions. That is, the force for separating the segment 12 and the insulator 11 is canceled out. For this reason, the separation between the segment 12 and the insulator 11 is further suppressed.

In addition, you may change each said embodiment as follows.
In the above embodiment, instead of the notch 17, a hole 18 may be provided as shown in FIG. Moreover, you may provide the recessed part 19 as shown in FIG. Even when configured in this manner, the same effects as those of the above-described embodiment can be obtained.

In the above embodiment, the notch 17 may be provided on the riser 14 side. Even in such a configuration, the same effects as the effects (1) and (2) of the above embodiment can be obtained.
In the above embodiment, the notches 17 are provided at a total of four locations for all of the first and second middle claws 15, 16, but may be provided at one or more. Further, a plurality of notches and holes may be provided in one middle nail.

  In the above embodiment, the notch 17 is formed when the metal plate member 20 is punched. However, the punching material 21 punched from the metal plate member 20 may be punched out.

  In the above embodiment, the first to third grooves 32 to 34 may be omitted. Even when the first to third grooves 32 to 34 are provided, the undercuts 32a to 34a may be omitted.

In the above embodiment, the groove portion 30 is configured by the two groove rows 31, but may be a single groove row 31.
In the above embodiment, the two groove rows 31 are provided along the longitudinal direction of the segment 12. However, the two groove rows 31 are not necessarily provided along the longitudinal direction.

In the above embodiment, the depth of the third groove 34 is deeper than that of the first and second grooves 32 and 33, but may be the same depth.
-In the said embodiment, it is good also considering the inclination direction of the undercuts 32a-34a as the same direction.

  In the above embodiment, two first and second middle claws 15 and 16 are provided, but one each may be provided. Further, the first and second middle claws 15 and 16 do not necessarily have to be paired in the longitudinal direction of the segment 12. Moreover, you may abbreviate | omit either the 1st and 2nd middle claws 15,16.

In the above embodiment, the number of segments 12 is 10. However, the number is not limited to this number, and can be appropriately changed according to the configuration.
In the above embodiment, the punching material 21 punched from the metal plate material 20 is rounded to form the cylindrical material 22, and then the segment 12 is formed by cutting. However, the segment 12 may be directly punched from the metal plate material 20. Good. Alternatively, the segment 12 may be formed by cutting the metal plate 20 and then cutting it.

DESCRIPTION OF SYMBOLS 10 ... Commutator, 11 ... Insulator, 11a ... Press-fit hole, 12 ... Segment (commutator piece), 13 ... Dividing groove, 14 ... Riser, 15 ... 1st middle nail | claw (locking piece), 16 ... 2nd inside Claw (locking piece), 17 ... notch (gripping part), 20 ... metal plate material, 21 ... punching material, 22 ... cylindrical material, 30 ... groove part, 31 ... groove row, 32-34 ... groove, 32a-34a ... under cut.

Claims (1)

A cylindrical insulator, and a plurality of commutator pieces that are made of a conductive plate material and are arranged in parallel in the circumferential direction on the outer peripheral surface of the insulator, and the commutator piece is in the axial direction of the insulator and from one end bent radially outwardly of the insulator in a connection pawl which armature windings are electrically connected, radially of the insulator from both ends in the axial direction of the insulator In a commutator that is bent toward the inside and includes a locking claw that locks the insulator,
The locking claws are a pair of first locking claws provided at both ends of the connecting claws in the axial direction of the commutator pieces and on both sides in the circumferential direction of the connecting claws, and A pair of second locking claws provided at an end opposite to the connection claw in the axial direction,
In each of the commutator pieces, the pair of first locking claws extend toward the second locking claws paired with each other in the axial direction,
In each commutator piece, the pair of first locking claws is a side part opposite to the side facing each other and only on the side part adjacent to the commutator piece side in the circumferential direction. A notch opening on the adjacent commutator piece side is formed, and the pair of second locking claws are adjacent to each other on the side opposite to each other and in the circumferential direction. A notch that opens to the adjacent commutator piece side is formed only on the side portion of the commutator piece side,
It said notch of the first locking claw and the second locking claw is commutator, wherein Rukoto configured as gripper for obtaining the anchor effect between the insulator.